PORCINE VALVE DURABILITY - A COMPARISON BETWEEN HANCOCK STANDARD AND HANCOCK-II BIOPROSTHESES

Two series of patients who received a Hancock standard (HS) (1970 to 1 983) and a Hancock II (HII) (1983 to 1992) porcine bioprosthesis were reviewed to compare bioprosthetic durability. Patients with HS porcine bioprostheses (n = 769) differed from those with HII bioprostheses mo stly in mean age at operation (47 +/- 12 versus 62 +/- 9 years; p < 0. 001); the latter prosthesis was implanted mostly in patients older tha n 50 years. At 8 years after operation, actuarial survival was 57% +/- 4% after aortic, 61% +/- 3% after mitral, and 39% +/- 7% after mitral -aortic valve replacement with the HS bioprosthesis; actuarial surviva l was 51% +/- 9% after aortic, 66% +/- 6% after mitral, and 49% +/- 10 % after mitral and aortic valve replacement with an HII bioprosthesis. No cases of structural deterioration of HII bioprostheses were observ ed at 8 years in any patients. Actuarial freedom from structural valve deterioration was 78% +/- 4% after aortic, 88% +/- 3% after mitral, a nd 79% +/- 7% after mitral-aortic valve replacement with an HS biopros thesis at 8 years. In all patients greater than 50 years of age, actua rial freedom from structural valve deterioration at 8 years was 90% +/ - 3% in patients with an HS bioprosthesis and 100% in those with an HI I bioprosthesis (p = 0.08). A trend to an improved durability of the H II bioprosthesis compared with the HS was observed during the first 8 postoperative years. Because these results could be influenced partly by the age difference in the two series of patients, a longer follow-u p is needed to confirm these data.